1. Field of the Invention
This invention relates to producing petroleum from a petroleum-containing subterranean formation employing a glucan. In particular, the glucan is employed with a clay flocculant.
2. Description of the Prior Art
Processes for the production of petroleum from a petroleum-containing subterranean formation employing an aqueous driving fluid containing a thickening agent is well known. U.S. Pat. No. 3,020,207 discloses such a process where the thickening agent is a heteropolysaccharide that has been reacted with an aldehyde, the heteropolysaccharide being a fermentation product produced by the action of bacteria of the genus Xanthomonas upon a carbohydrate. U.S. Pat. No. 3,352,358 discloses a process employing thickened aqueous driving fluid where the thickening agent is polyvinyl alcohol sulfate. U.S. Pat. No. 3,372,749 also discloses a process employing thickened aqueous driving fluid where the thickening agent is a poly(glucosylglucan). In the process disclosed in U.S. Pat. No. 3,373,810, the thickening agent for the aqueous driving fluid is sulfoalkylated poly(glucosylglucan), a sulfoalkylated polysaccharide or a mixture of both, the polysaccharide being the heteropolysaccharide produced by the action of the bacterium Xanthomonas coampestris on glucose.